1. Technical Field
The present invention relates to a working method and apparatus for holding by suction a work object (for example, a semiconductor component such as an IC chip) to be placed on a work stage, moving the work object to a specified position, regulating the object in position, and thereafter subjecting the work object to specified work (for example, bump bonding work of bumps formed on an IC chip), and in particular, to a bump bonding working method and apparatus for holding by suction a work object of, for example, a semiconductor component such as an IC chip in which a semiconductor device is formed, to be placed on a work stage, moving the semiconductor component to a specified position, regulating the component in position, and thereafter subjecting the component to specified work such as bump bonding work of a bump that serves as a protruding electrode formed on an electrode of, for example, a semiconductor component: and an IC chip obtained through the processes.
2. Description of Related Art
Regarding semiconductor components such as the so-called IC chips and the like in which semiconductor elements having an integrated circuit are formed, in accordance with the miniaturization of electronic components, the compacting of a circuit board, increasing integration density, and increasing mounting density on a circuit board, there is frequently adopted the so-called surface mounting for collecting electrodes on a surface to be mounted on a circuit board, electrically connecting face to face the electrodes to corresponding electrodes and conductor lands of the circuit board and concurrently bonding them together into an integrated body with solder or adhesive for mounting.
It has already been known to form metal bumps on the electrodes of an IC chip for this surface mounting and easily achieve individual electrical connections with the circuit board. The present applicant has previously provided and put into practical use a bump bonding method by means of a wire bonding method as a method for forming a metal bump.
The outline of this method will be explained with reference to FIG. 14 and FIGS. 5A through 5D. Using an IC chip 1 as a work object, this work presses a metal wire 3 against an electrode 2 of a surface 1a thereof with ultrasonic vibrations applied to the wire for the achievement of metallic bond as shown in FIGS. 5A through 5D and separates the succeeding metal wire 3 from a bonded metal lump 3a formed through the above process by tearing off or cutting by pushing the metal wire 3, forming a metal bump 4 on the electrode 2.
Specifically, FIG. 14 is a perspective view of a bump bonding apparatus for forming a bump on the IC chip 101 with a gold wire 113.
In FIG. 14, the IC chip 101 supplied from a tray 110 is held by suction by a suction nozzle 1111, thereafter moved by the suction nozzle 111 and fixed to an IC chip placement surface or, for example, the upper surface of a stage 151 that has a raised temperature. A capillary 112 is constructed so as to be held by an ultrasonic wave supply unit and receive ultrasonic waves, and a gold bump is formed on the electrode of the IC chip 101 by the capillary 112 through which the gold wire 113 is positioned. The IC chip 101 that has undergone bump formation in the required portions is held by suction by the suction nozzle 111 and stored in another tray 110a. 
FIGS. 5A through 5D are process charts showing the bump forming process performed by the aforementioned conventional bump bonding apparatus.
First of all, in the process of FIG. 5A, a gold wire 3 is put through the capillary 34, and the tip of the gold wire 3 is sparked, forming a spherical ball portion 3a at the tip.
Next, in the process of FIG. 5B, the capillary 34 is lowered to press the spherical ball portion 3a located at the tip against the electrode 2 of the IC chip 1. At this time, ultrasonic waves are applied to bond the gold wire 3 to the electrode 2 (first bonding).
Next, in the process of FIG. 5C, the capillary 34 is moved up and moved down again while being controlled so as to move in a loop form. As shown in the process of FIG. 5D, the capillary 34 presses the gold lump that has undergone the first bonding, cutting the gold wire 3 (second bonding).
The following will describe in detail the position regulating section of the IC chip 1 of the aforementioned conventional bump bonding apparatus.
FIGS. 6, 15A, 15B and 15C are a flowchart of a position regulating operation and plan views of the position regulating section of the IC chip 1.
As shown in FIG. 15A, the position regulating section of the bump bonding apparatus is constructed of a stage 151 provided with four suction holes 157 and an L-figured position regulating pawl 152 that can move in XY-directions. The IC chip 1 is moved on the suction holes 157 of the stage 151 by the position regulating pawl 152 and regulated in position on the stage 151 while being sucked by vacuum. Describing this operation based on the flowchart, as shown in FIG. 13, suction is first turned on by a vacuum pump to start suction (step S51), and the IC chip 1 held by suction by the suction nozzle 111 is placed on the stage 151 of the bump bonding apparatus. The IC chip 1 is sucked by the suction holes 157 (step S52, see FIG. 15A), and the position regulating pawl 152 is moved on the stage 151 to regulate in position the IC chip 1 by means of a constant suction force (step S53, see FIG. 15B). That is, in this FIG. 15B, the IC chip 1 is first moved leftward by the position regulating pawl 152 and thereafter moved upward to perform positioning, and the IC chip 1 is held by suction by the four suction holes 157. Subsequently, after the IC chip 1 is positioned, the position regulating pawl 152 is moved back from the position of the solid line to the position of the one-dot chain line (step S53, see FIG. 15C), release regulation is performed (Step S54), and thereafter the IC chip 1 is bonded, according to the conventional practice (Step S55).
In attempting to further increase the speed and quality in practically using this wire bonding method and apparatus, the present applicant has found visible minute scratches on a surface 1b that belongs to the IC chip 1 and is located opposite from the mounting surface 1a on which the metal bumps 4 are formed for the bonding onto a circuit board or the like. Since the surface is to be noticed as the identification surface of the manufacturer name, article number, specifications and so on, such scratches are concerned with the quality in terms of the external appearance although the scratches lead to no functional defect. Depending on the size and depth of the scratches, it can be considered that the scratches would become the cause of chipping and cracking due to an impact or the like at the time of handling in various stages, and this has became an important issue.
The present inventor and others have conducted various experiments in order to solve this issue and discovered the following facts. To the stage 151 are adhering foreign objects such as processing dust occurring when dicing is performed for separation into individual IC chips 1, chipped segments generated during processing, conveying and various handling processes, dust in the air and so on, each having a particle diameter of two to several tens of micrometers. The processing dust and chip dust as described above are often hard substances of the grindstone that has performed dicing and those of the processed IC chips, having hardness equivalent to that of the IC chip 1. Therefore, when the IC chip 1 is regulated in position by being pushed from the placement position to the work position in a state in which it is sucked onto the work stage 151, the IC chip suffers scratches while being brought in strong abrasive contact with the foreign objects, occasionally causing chipping and cracking. That is, according to the aforementioned structure and method, the IC chip 1 is loaded with a suction force required for bonding from the suction holes 157 even when the IC chip 1 is regulated in position. Therefore, a heavy load is applied to the IC chip 1 when the IC chip 1 is moved in a contact portion where a peripheral portion of the IC chip 1 comes in contact with a peripheral portion of the position regulating pawl 152, and this has damaged the peripheral portion of the IC chip 1. Moreover, a great frictional force is exerted between the IC chip 1 and the stage 151, and this has inflicted damage on the IC chip 1. Moreover, the fragments of the damaged IC chip 1 remain on the stage 151, and this has aggravated the damage on the IC chip 1 placed subsequently. The above-mentioned issues have not been able to be removed in the conventional work environment of dicing work with washing in water, work inside a clean room and so on.
There are some IC chips 1 constructed of a single crystal semiconductor of silicon or the like or a compound semiconductor of gallium arsenide or the like. The silicon semiconductor is hard and tends to cause chipping and cracking. The compound semiconductor such as gallium arsenide is soft and tends to suffer scratches, and in addition, it is fragile and tends to incur chipping and cracking. On the other hand, the bump bonding work is performed with the IC chip 1 held by suction in the work position. Therefore, although the foreign objects scarcely cause scratches during the above work, a bonding temperature of not lower than 250xc2x0 C. and the application of ultrasonic vibrations with a pressure of about 30 g exert influence. If a foreign object as described above is interposed between the IC chip and the work stage 151, then the IC chip 1 tends to incur chipping and cracking, and in addition, the ultrasonic vibrations themselves become hard to produce an effect, easily causing a bonding failure. Therefore, electronic components like semiconductor components such as IC chips are required to suffer a reduced impact force and a reduced load at the position regulating time, for the prevention of damage on the electronic components.
On the basis of the aforementioned knowledge, the present invention has the object of providing a working method and apparatus that ensures improved quality of the state of the product surface opposite from the mounting surface and are hard to cause chipping and cracking as well as a high-quality IC chip obtained by the method and apparatus.
In order to achieve the aforementioned object, the present invention has the following construction.
According to a first aspect of the present invention, there is provided A working method for holding by suction a work object placed on a work stage, moving the work object into a specified position, regulating in position the object, and thereafter subjecting the object to specified work, comprising:
receiving the work object to be placed on a work object placement surface of a roughened surface of the work stage; holding by suction the work object while supporting the work object with protruding portions of the roughened surface of the work object placement surface of the work stage;
thereafter changing an immovable state in which the object is held by suction into a movable state for positional regulation; and thereafter regulating in position the work object while stably moving the work object on the work stage in a frictional state obtained by supporting the work object with the prot ruding portions of the roughened surface of the work object placement surface of the work stage and while restraining strong abrasive movement of a foreign object between the work stage and the work object in moving the work object for positional regulation by pockets that are formed of recess portions around the protruding portions and let the foreign object escape.
In the above-mentioned construction, by holding by suction the work object placed on the work stage, the positional regulation of the work object from the receiving position to the specified position on the work stage is performed by the movement in the state in which the suction to the work stage is reduced or released while allowing the work object placed by a variety of methods to be securely received and accepted inclusive of the influence when the release of vacuum is delayed in conveying and placing the object held by suction by the suction nozzle. Therefore, no strong abrasion occurs even if a foreign object is interposed between the object and the work stage, and this prevents the surface of the work object put in contact with the work stage from suffering scratches, chipping or cracking, allowing the quality and yield of products to be improved.
According to a second aspect of the present invention, there is provided a working method as defined in the first aspect, wherein the movable state for positional regulation is a state in which the suction of the work object is reduced or released.
According to a third aspect of the present invention, there is provided a working method as defined in the first or second aspect, wherein the work object is regulated in position in the movable state for positional regulation, thereafter the work object is sucked again to put the work object into the immovable state, and thereafter, the work object is subjected to the specified work.
In the above-mentioned construction of the second and third aspects, suction is further performed again when subjecting to work the work object regulated in position on the work stage in addition to the first aspect. Therefore, the displacement ascribed to the work load of the work object is securely prevented by obtaining a sufficient suction state capable of enduring the work load without influence ascribed to the difference of the previous suction state from the suction state during work by virtue of the reduction and release of suction performed in positional regulation, by which the work is achieved with high accuracy, allowing a quality product to be provided.
According to a fourth aspect of the present invention, there is provided a working method as defined in any one of the first through third aspects, wherein the specified work is performed after starting the suction of the work object in the immovable state by turning on a suction device exclusively for work set in correspondence with the work.
In the above-mentioned construction of the fourth aspect, the specified work is performed after starting the suction by the suction device used exclusively for the work. Therefore, a suction state appropriate for performing the specified work can be immediately obtained without adjustment of the suction state or the like regardless of the previous suction state, by which high-accuracy work can be achieved with little time loss, allowing the quality of the work object to be improved without reducing the work efficiency.
According to a fifth aspect of the present invention, there is provided a working method as defined in any one of the first through fourth aspects, wherein the work object is an IC chip, the positional regulation is performed with use of the work stage whose IC chip placement surface that serves as the work object placement surface is a roughened surface, the recess portions provided around the protruding portions of the roughened surface that serve as the work object placement surface form pockets for letting the foreign object escape to restrain influence of the foreign object exerted on the IC chip when the bump bonding work is performed as the specified work with the IC chip subjected to heating to a bump bonding temperature of the bump bonding work, a pressure load, and a vibration load.
In the above-mentioned construction of the fifth aspect, numbers of support points of the protruding portions are existing in spots on the roughened surface between the work stage and the work object including the IC chip supported on the work stage, and the work object is stably moved on the work stage by obtaining appropriate frictional state, achieving high-accuracy positional regulation even if the release and reduction of the suction is performed. The recess portions provided around the protruding portions form pockets for letting the foreign object escape to restrain the strong abrasive movement of the foreign object between the work stage and the work object when the work object is moved for positional regulation and restrain the influence of the foreign object exerted on the work object when the work object is subjected to work with a pressure load and a vibration load as in the bump bonding work, which might additionally be accompanied by heating. Therefore, the work object can be prevented from suffering scratches, chipping and cracking by the foreign object when the work object is regulated in position or subjected to work with a variety of work loads.
The recess portions provided around the protruding portions are continued to one another to form pathways for dissipating the suction force in the reducing and releasing phase, and therefore, early reduction or early release of the suction is achieved, allowing the position regulating work to start early and allowing the operation efficiency to be improved.
According to a sixth aspect of the present invention, there is provided a working method as defined in any one of the first through fifth aspects, wherein the work object is an IC chip and the specified work is a bump bonding work for applying heat to the IC chip from the work stage side, pressing a metal wire against an electrode of the IC chip with ultrasonic vibrations applied to the metal wire and thus achieving metallic bond, and forming a metal bump on the IC chip by separating a succeeding metal wire from a bonded metal lump formed through the processes.
In the above-mentioned construction of the sixth aspect, when the above-mentioned work is the bump bonding work for applying heat from the work stage side to the IC chip, pressing the metal wire against the electrode of the IC chip with ultrasonic vibrations applied for the achievement of metallic bond and thereafter separating the succeeding metal wire from the bonded metal lump formed through the above processes, for the formation of the metal bump on the IC chip, even if the position regulating work is performed with a foreign object such as a processing dust interposed between the surface that belongs to the IC chip and is located opposite from the mounting surface onto the circuit board on which the bump bonding work of the IC chip is performed and the IC chip placement surface of the work stage, no strong abrasion occurs with respect to the foreign object by virtue of the reduction or release of the suction while securing the reception and acceptance of the IC chip placed on the work stage by suction. This prevents the surface from suffering scratches, chipping or cracking and allows the production of high-quality IC chips provided with bumps having no scratch on the surface with high yield.
According to a seventh aspect of the present invention, there is provided a working method as defined in the first aspect, wherein
the specified work is bump bonding, the work object is an electronic component, and a suction force for sucking the electronic component onto the work stage through a suction hole of the work stage that has the suction hole for holding by suction the electronic component is switched between at least two types of a first suction force with which the electronic component is held by suction to such an extent that the electronic component can move along the stage on the stage and a second suction force, which is stronger than the first suction force and with which the electronic component is held by suction to such an extent that the electronic component cannot move along the stage on the stage, the working method comprising:
a process for switching the suction force to the second suction force;
a process for placing the electronic component on the stage and holding by suction the electronic component with the second suction force through the suction hole of the stage;
a process for switching the suction force for sucking the electronic component to the stage through the suction hole of the stage from the second suction force to the first suction force;
a position regulating process for moving the electronic component by a position regulating member for positioning while holding by suction the electronic component with the first suction force on the stage;
a process for immovably holding by suction the positioned electronic component on the stage by switching the suction force from the first suction force to the second suction force; and
a process for performing bump bonding that serves as the specified work.
According to an eighth aspect of the present invention, there is provided a working method as defined in the first aspect, wherein
the specified work is bump bonding, the work object is an electronic component, and a suction force for sucking the electronic component onto the stage through a position regulating suction hole of the work stage that has the position regulating suction hole for holding by suction the electronic component is switched between at least two types of a first suction force with which the electronic component is held by suction to such an extent that the electronic component can move along the stage on the stage and a second suction force, which is stronger than the first suction force and with which the electronic component is held by suction to such an extent that the electronic component cannot move along the stage on the stage, the working method comprising:
a process for switching the suction force to the second suction force;
a process for placing the electronic component on the stage and holding by suction the electronic component with the second suction force through the position regulating suction hole of the stage;
a process for switching the suction force for sucking the electronic component to the stage through the position regulating suction hole of the stage from the second suction force to the first suction force;
a position regulating process for moving the electronic component by a position regulating member for positioning while holding by suction the electronic component with the first suction force on the stage;
a process for immovably holding by suction the positioned electronic component on the stage by means of the position fixing suction hole of the stage; and
a process for performing bump bonding that serves as the specified work.
According to a ninth aspect of the present invention, there is provided a working method as defined in the seventh or eighth aspect, wherein heat is applied to the electronic component via the stage, making the electronic component have a bump bonding temperature.
According to a tenth aspect of the present invention, there is provided a working apparatus comprising:
a work stage having suction holes for holding by suction a work object in a receiving position for receiving the work object to be placed on a work object placement surface that is a roughened surface and a work position in which the work object is moved from the receiving position to a specified position so as to be regulated in position and subjected to work;
a position regulating member for regulating in position the work object located in the receiving position of the work stage by pushing the object into the work position;
a suction mechanism for holding by suction the work object through the suction hole of the work stage in the receiving position and the work position of the work stage; and
control means for controlling the suction mechanism so as to put the work object into an immovable state by holding by suction the work object while supporting the work object with protruding portions of the roughened surface of the work object placement surface of the work stage when the work object is placed and received in the receiving position on the work object placement surface of the roughened surface of the work stage, thereafter change an immovable state in which the object is held by suction into a movable state for positional regulation, thereafter regulate in position the work object into the work position while stably moving the work object on the work stage in a frictional state obtained by supporting the work object with the protruding portions of the roughened surface of the work object placement surface of the work stage and while restraining strong abrasive movement of a foreign object between the work stage and the work object in moving the work object for positional regulation by pockets that are formed of recess portions around the protruding portions and let the foreign object escape, put the work object regulated in position into the immovable state by sucking the object again, and thereafter subject the object to specified work.
According to the above-mentioned tenth construction, the working method of the first aspect can be automatically stably achieved at high speed.
According to an 11th aspect of the present invention, there is provided a working apparatus comprising:
a work stage having suction holes for holding by suction a work object in a receiving position for receiving the work object to be placed and a work position in which the work object is moved from the receiving position to a specified position so as to be regulated in position and subjected to work;
a position regulating member for regulating in position the work object located in the receiving position of the work stage by pushing the object into the work position;
a suction mechanism for holding by suction the work object through the suction hole of the work stage in the receiving position and the work position of the work stage; and
control means for controlling the suction mechanism so as to put the work object into an immovable state by holding by suction the work object when the work object is placed and received in the receiving position on the work stage, thereafter change the immovable state in which the object is held by suction into a movable state for positional regulation, thereafter regulate in position the object into the work position, put the work object regulated in position into the immovable state by sucking the object again, and thereafter subject the object to specified work, wherein
the suction mechanism is provided with a first suction system for holding by suction the work object in the receiving position and a second suction system for holding by suction the work object in the work position; and
the control means controls the first and second suction systems of the suction mechanism so as to put the work object into the immovable state by holding by suction the object by the first suction system when the work object is placed and received in the receiving position on the work stage, thereafter change the immovable state in which the object is held by suction into the movable state for positional regulation by temporarily reducing or releasing the suction, thereafter regulate in position the object into the work position, put the work object regulated in position into the immovable state by sucking the object again by the second suction system, and thereafter subject the object to specified work.
In the 11th construction, in addition to the working method of the first aspect, the method of the second and third aspects can be automatically stably accomplished at high speed.
According to a 12th aspect of the present invention, there is provided a working apparatus as defined in the eleventh aspect, wherein
the first suction system has first and second suction holes in a position corresponding to the work object located in the receiving position and in a position located apart from the work object held by suction in the receiving position, respectively, and the second suction system has suction holes in positions corresponding to the work object located in the work position.
According to the above-mentioned 12th aspect, the first suction system is provided with the first and second suction holes located in the position corresponding to the work object in the receiving position and the position located off the work object held by suction in this receiving position, while the second suction system is provided with the suction hole located in the position corresponding to the work object in the work position. With this arrangement, while securely receiving by suction the work object placed in the receiving position of the work stage by the suction further through the first suction hole of the first suction system in addition to the working apparatus of the second characteristics, the second suction hole is in the open state in which the hole is not facing the work object when reducing or releasing the suction for the next positional regulation and operates as a hole for releasing the suction force for reducing the suction. This enables the reduction or release of suction in an early stage, and accordingly, there is no influence of the suction even if a time lag in which the work object is shifted from the reception to the positional regulation is reduced. Therefore, the scratches, chipping and cracking due to the foreign object can be prevented to allow the positional regulation to be achieved, and the work efficiency can be improved without causing a reduction in quality. The second suction system can securely hold the work object concurrently with the positional regulation of the object without any issue by virtue of the suction through the suction hole that is facing the work object regulated in position and perform the work in an early stage after the positional regulation of the work object. Therefore, the work efficiency can be improved also in this aspect.
According to a 13th aspect of the present invention, there is provided a working apparatus as defined in the 12th aspect, wherein the second suction hole of the first suction system is provided in a position corresponding to the work object located in the work position.
According to the 13th aspect, if the second suction hole of the first suction system is provided in the position corresponding to the work object in the work position, then the work object gradually approaches the second suction hole as the work object is moved gradually apart from the first suction hole in the course of the positional regulation of the work object into the work position. Accordingly, there is the advantage that the required reduced suction force can be exerted during the period from the start phase to the end phase of positional regulation when the state of the reduced suction is achieved during the positional regulation period.
According to a 14th aspect of the present invention, there is provided a working apparatus comprising: a work stage having suction holes for holding by suction a work object, a receiving position for receiving the work object to be placed, and a work position in which the work object is moved from the receiving position to a specified position so as to be regulated in position and subjected to work; a position regulating member for regulating in position the work object located in the receiving position of the work stage by pushing the object into the work position; and a suction mechanism for holding by suction the work object through the suction hole of the work stage in the receiving position and the work position of the work stage,
the work stage having an IC chip placement surface processed by electric discharge.
According to the 14th aspect, the IC chip placement surface of the work stage is formed by the electric discharge process into the roughened surface of an almost constant specified roughness by comparison with the case of the surface processing achieved by another method such as blasting. Therefore, the feature of the roughened surface obtained by the working method of the fourth aspect of the present invention can be stably put into effect regardless of the difference in position of the IC chip placement surface of the work stage and the difference of the working apparatus, allowing the work to be stabilized.
According to a 15th aspect of the present invention, there is provided a working apparatus as defined in any one of the 10th through 14th aspects, comprising a work mechanism for subjecting the work object to the specified work every time the work object is held by suction in the work position on the work stage, the work mechanism being a bump bonding mechanism for pressing a metal wire against an electrode of an IC chip that serves as the work object with ultrasonic vibrations applied to the wire for achievement of metallic bond and forming a metal bump on the electrode by separating the succeeding metal wire from a bonded metal lump formed through the above processes.
According to the above-mentioned 15th aspect, the working apparatus of which the work is the bump bonding for forming the metal bump on the electrode of the IC chip is provided with a work mechanism for performing a specified work on the IC chip every time the IC chip is held by suction in the work position on the work stage. This work mechanism is merely required to be a bump bonding mechanism for pressing the metal wire against the electrode of the IC chip that serves as the work object with ultrasonic vibrations applied for the achievement of metallic bond and thereafter separating the succeeding metal wire from the bonded metal lump through the above processes, for the formation of the metal bump on the electrode. If the heat source for heating the IC chip is in operation, then the work stage has the advantage that the metallic bond can be promoted to allow the bump bonding work to be securely achieved in a short time.
According to a 16th aspect of the present invention, there is provided a working apparatus as defined in the 15th aspect, wherein the work stage has a heat source operating to heat the IC chip.
According to a 17th aspect of the present invention, there is provided a working apparatus as defined in any one of the 10th through 16th aspects, wherein the work stage is mounted so as to be replaceable.
According to the 17th aspect, if the work stage is mounted so as to be replaceable, then the maintenance work required for a change due to the wearing of the roughened surface state and the work of replacing the work stage with the one that has a roughened surface corresponding to the type of the IC chip every time the IC chip is changed can be achieved on optimum conditions, which is preferable.
According to an 18th aspect of the present invention, there is provided an IC chip provided with a bump, which has no visible scratch on a surface opposite from a mounting surface on which a metal bump is bonded onto an electrode.
According to the 18th aspect, the IC chip provided with bumps has no visible scratch on the surface opposite from the mounting surface on which the metal bumps are bonded onto the electrode and is easily stably obtained by the aforementioned working method and working apparatus. This also eliminates the occurrence of visible scratches on the surface to be noticed not only in the electronic component state but also after the mounting of the component on a circuit board and assembled into equipment as well as the causes of scratches, chipping and cracking due to impact or the like during handling or the like, and therefore, high reliability can be ensured.
According to a 19th aspect of the present invention, there is provided a working apparatus as defined in the 10th aspect, wherein
the work object is an electronic component, and
the control means comprises a suction force control section that subjects the suction force for sucking the electronic component to the stage through the suction hole on the stage to switching control between at least two types of a first suction force with which the electronic component is held by suction in the state in which the electronic component can move along the stage on the stage and a second suction force, which is stronger than the first suction force and with which the electronic component is held by suction in the state in which the electronic component cannot move along the stage on the stage, sets the suction force for sucking the electronic component to the first suction force when the electronic component is moved for positioning while being held by suction on the stage and sets the suction force to the second suction force when the electronic component is received on the stage before being positioned and when the positioned electronic component is held by suction on the stage in the immovable state.
According to a 20th aspect of the present invention, there is provided a working apparatus as defined in the tenth aspect, wherein
the work object is an electronic component, and
the control means comprises a suction force control section that subjects the suction force for sucking the electronic component to the stage through the suction hole on the stage to switching control between at least two types of a first suction force with which the electronic component is held by suction in the state in which the electronic component can move along the stage on the stage and a second suction force, which is stronger than the first suction force and with which the electronic component is held by suction in the state in which the electronic component cannot move along the stage on the stage, sets the suction force for sucking the electronic component to the first suction force when the electronic component is moved for positioning while being held by suction on the stage and sets the suction force to the second suction force in order to hold by suction the positioned electronic component on the stage in the immovable state when the electronic component is received on the stage before being positioned, and
the electronic component regulated in position is fixed in position by suction by the position fixing suction hole of the stage.
According to a 21st aspect of the present invention, there is provided a working apparatus as defined in the 19th or 20th aspect, wherein a heater is arranged inside the stage, and heat for bump bonding is applied to the electronic component.
According to a 22nd aspect of the present invention, there is provided an IC chip having undergone the bump bonding by the working method defined in the sixth aspect.
According to a 23rd aspect of the present invention, there is provided an electronic component having undergone the bump bonding by the working method defined in any one of the seventh through ninth aspects.
According to a 24th aspect of the present invention, there is provided a working apparatus comprising:
an immovably fixed work stage having suction holes for holding by suction a work object in a receiving position for receiving the work object to be placed and a work position in which the work object is moved from the receiving position to a specified position so as to be regulated in position and subjected to work;
a position regulating member for regulating in position the work object located in the receiving position of the work stage, which can be moved in two directions that are perpendicular to each other and located in a work object placement surface of the work stage by pushing the object into the work position on the work stage;
a suction mechanism for holding by suction the work object through the suction hole of the work stage in the receiving position and the work position of the work stage; and
control means for controlling the suction mechanism so as to put the work object into an immovable state by holding by suction the work object when the work object is placed and received in the receiving position on the work stage, thereafter change the immovable state in which the object is held by suction into a movable state for positional regulation, thereafter regulate in position the object into the work position, put the work object regulated in position into the immovable state by sucking the object again, and thereafter subject the object to specified work.
According to a 25th aspect of the present invention, there is provided a working method for holding by suction a work object placed on a work stage, moving the work object into a specified position, regulating in position the object, and thereafter subjecting the object to specified work, comprising:
receiving an IC chip that serves as the work object to be placed on an IC chip placement surface of a roughened surface of the work stage; holding by suction the IC chip while supporting the IC chip by protruding portions of the roughened surface of the IC chip placement surface of the work stage;
thereafter changing an immovable state in which the object is held by suction into a movable state for positional regulation; and thereafter providing pockets that are formed of recess portions provided around the protruding portions of the roughened surface serving as the IC chip placement surface and let the foreign object escape to restrain influence of the foreign object exerted on the IC chip when the bump bonding work is performed with the IC chip subjected to heating to a bump bonding temperature of the bump bonding work, a pressure load, and a vibration load.
According to a 26th aspect of the present invention, there is provided a working apparatus comprising:
a work stage having suction holes for holding by suction a work object in a receiving position for receiving the work object to be placed on the work object placement surface that is a roughened surface and a work position in which the work object is moved from the receiving position to a specified position so as to be regulated in position and subjected to work;
a position regulating member for regulating in position the work object located in the receiving position of the work stage by pushing the object into the work position;
a suction mechanism for holding by suction the work object through the suction hole of the work stage in the receiving position and the work position of the work stage;
control means for controlling the suction mechanism so as to put the work object into an immovable state by holding by suction the work object when the work object is placed and received in the receiving position on the work object placement surface of the roughened surface of the work stage, thereafter change the immovable state in which the object is held by suction into a movable state for positional regulation, thereafter regulate in position the object into the work position, put the work object regulated in position into the immovable state by sucking the object again, and thereafter subject the object to specified work; and
a work mechanism for subjecting the work object to the specified work every time the work object is held by suction in the work position on the work stage,
the work mechanism being a bump bonding mechanism for pressing a metal wire against an electrode of an IC chip that serves as the work object with ultrasonic vibrations applied to the wire for achievement of metallic bond and forming a metal bump on the electrode by separating the succeeding metal wire from a bonded metal lump formed through the above processes, and
pockets formed of recess portions provided around the protruding portions of the roughened surface serving as the IC chip placement surface escaping the foreign object to restrain influence of the foreign object exerted on the IC chip when the bump bonding work is performed with the IC chip subjected to heating to a bump bonding temperature of the bump bonding work, a pressure load, and a vibration load by the bump bonding mechanism.
The features of the aspects of the present invention can be each used singly as far as possible and also in a variety of combinational complex forms.